A toilet seat typically comprises a seat ring which can be pivoted between a raised and a lower position, possibly a lid which can also be pivoted between a raised and lowered position, and a fixing arrangement for mounting the seat ring and possibly the lid on a toilet pan or bowl in a rearward region thereof.
The seat ring and the lid if provided occupy a stable position, in their condition of being pivoted upwardly, when the angle between their horizontal position and the upwardly pivoted position is greater than 90.degree.. In the case of typical toilet seat assemblies the mounting eye members for pivotably mounting the seat and possibly the lid are respectively disposed in the region of the rearward end of the assembly. That means that, in order to afford a stable raised position, the arrangement must be so designed that, on the side of the pivot axis which is opposite to the seat ring, there is in an upward direction sufficient space for the seat ring and possibly the lid if provided to be pivoted into the stable raised position. In many situations however that space does not exist, for example and more particularly if the toilet has a flush tank or cistern which extends upwardly from the upper edge of the toilet pan or bowl, in the rearward end region thereof. The presence of the flush tank at that position would prevent the seat from moving beyond the 90.degree. position in going from the lowered position to the raised position. Accordingly, in order also to afford a stable raised position in such situations, the pivot axis mounting the seat ring is displaced forwardly in a horizontal direction by a suitable distance so that the angle between the horizontal or lowered position of the seat ring and the raised position thereof is once again an obtuse angle, with the seat ring thus `leaning against` the flush tank. A design configuration which is often adopted in such cases is to employ a plate-like portion which can be referred to herein as the back plate portion and which adjoins the rearward end of the seat ring in the horizontal position of the seat ring and the lid if provided, thereby filling the space between the rearward end of the seat ring and the rearward end of the toilet pan. The back plate portion thus has the effect of moving forwardly the pivot axis about which the seat ring pivots and for that purpose is fixedly mounted to the toilet pan.
The production of a back plate portion of that kind, which generally comprises plastic material, is relatively expensive as adjustable or displaceable fixing devices usually have to be provided, having regard to the existence of toilet pans of different configurations. Accordingly such toilet seat assemblies are therefore more expensive to produce than a toilet seat assembly which does not have a back plate portion.
A further problem which may arise is that it is difficult to produce the back plate portion and the other parts of the toilet seat in exactly the seine color, in particular when for example the seat ring essentially consists of wood while the back plate portion is in the form of a plastic member. A further disadvantage is that toilet seats with a back plate portion are in principle unsatisfactory from the point of view of visual attraction as the transitional region between the rearward end of the seat ring and the front edge of the back plate portion is always visible.